Evstigneeva Z G, Solov'eva N A, Sidel'nikova L I
Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071 Russia.
Prikl Biokhim Mikrobiol. 2003 Nov-Dec;39(6):613-8.
Derivatives of methionine sulfoximine (MSO) and phosphinothrycin (PPT), which are analogues of glutamate, exhibit selective herbicidal activity. This effect is accounted for by impairments of nitrogen metabolism, resulting from inhibition of its key enzyme in plants, glutamine synthetase (EC 6.3.1.2). Inhibition of the enzyme causes ammoniac nitrogen to accumulate and terminates the synthesis of glutamine. Changes in the content of these two metabolites (excess ammonium and glutamine deficiency) act in a concert to cause plant death. However, low concentrations of MSO, PPT, and their metabolites produce an opposite effect: glutamine synthetase is activated, with concomitant stimulation of plant growth and productivity. The mechanisms whereby MSO and PPT affect glutamine synthetase activity are discussed in the context of nitrogen metabolism in plants.
甲硫氨酸亚砜亚胺（MSO）和草丁膦（PPT）的衍生物是谷氨酸的类似物，具有选择性除草活性。这种效应是由于植物中关键酶谷氨酰胺合成酶（EC 6.3.1.2）受到抑制，导致氮代谢受损所致。该酶的抑制会使氨态氮积累，并终止谷氨酰胺的合成。这两种代谢物含量的变化（过量的铵和谷氨酰胺缺乏）共同作用导致植物死亡。然而，低浓度的MSO、PPT及其代谢物会产生相反的效果：谷氨酰胺合成酶被激活，同时刺激植物生长和提高生产力。本文结合植物氮代谢来讨论MSO和PPT影响谷氨酰胺合成酶活性的机制。
